Heat exchanger



Nov. 21, 1944. J. w. BROWN, JR

HEAT EXCHANGER Filed Dec; 24, 1941 3 Sheets-Sheet l aamv w. 320w, we.

BY .Y flawxz'mwm yin A TTORNEYS.

NOV; 21, 194-4.

J. w. BROWN. JR

HEAT EXCHANGER Filed Dec.. 24, 1941.;

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Nov. 21, 1944.-

J w. BROWN, JR

HEAT EXCHANGER Filed Dec. 24, 1941 5 Sheets-Sheet 5 Q INVENTOR. r/OHN w.520w, =72. BY 5 flTTO/QNEVJ disconnected.

Patented Nov. 21, 1944 UNITED STATES PATENT orricr.

HEAT EXGHANGER I I John W. Brown, Jr., Lakewood, Ohio, assignor toporation of Ohio Brown Fintube Company, Elyria, Ohio, a cor- ApplicationDecember 24, 1941, Serial No. 424,241

3 Claims.

This invention relates to heat exchangers and more particularly -to heatexchangers particularly adapted to take advantage of the heattransferring capacity of finned tubes such as those described -in myPatents Nos. 2,261,136 and 2,261,137, issued November 4, 1941, althoughother types of heat exchange conductors may be incorporated therein.

heat exchanger embodying my invention; and

Figs. 10, 11 and 12 are transverse sections as indicated by the linesll0, ll- H and l2 -.l2, respectively, of Fig. 9.

Referring to Figs. 1 to 5, a heat exchanger made according to a.preferred form of my invention A general object of my invention is toprovide,

an eflicient heat exchanger which is compact and which can beeconomically manufactured. Another object is to provide a-heatexchangerembodying a finned tube and arranged to utilize the high heat transferefliciency of the tube. Another object of my invention is to provide aheat exchanger which-may be readily cleaned and in which the entirecleaning operation can be carried out from one end of the exchanger.Another flow principle within and outside of a single tube. A furtherobject is to provide such a heat ex-' changer which can be adapted tovarious uses and purposes, and which may be designed to embody variousmass-flow characteristics depending upon the service for which theexchanger is intended.

Further objects and advantages of my invention will become apparent fromthe followingdescription of preferred forms thereof, reference beingmade to theaccompanying drawings where in Fig. 1 is a longitudinalsection through a heat exchanger made according to my invention; Fig. 2is a transverse section taken along'the line 22 of Fig. 1; Fig. 3 is atransverse section taken along the line 3-3 of Fig. 1; Fig. 4. is afragmentary longitudinal section taken on a plane at" right angles tothe planeof Fig. 1 as indicated by the line l-Jof Fig. 1; Fig. 5 is afragmentary section as indicated by the line 5-5 of Fig.2; Fig. 6 is alongitudinal section through another form of heat exchanger embodying myinvention; Fig. 7 is a transverse section taken along the'line of Fig.6; Fig. 8 is atransverse section taken along the line 8-8 of Fig. 6;Fig. 9 is a longitudinal section through a third form of may comprise aheader l0, shown here as being a header for a single unit, but which canbe constructed to accommodate a number of heat exchanger units Theheader may be a forging or casting, and is provided with inlet andoutlet openings l I and I2, respectively, in which the conduits l3 andI4, terminating in conventional flanged couplings, are suitably secured,for example, by welding'as shown. The inlet and outlet passageways jointo former central chamber l5 communicating-with the interior of the tubeIt .which is preferably welded as at l1 into the counter-bored openingl8 in the header; The tube is preferably provided with a plurality ofchannel section fins I9, preferably of the type more particularlydescribed in my aforesaid patents, to assist in transfer of heat fromthe commodity within the tube to the commodity on the exterior of thetube. The construction of the fins will be described in greater'detailbelow.

To cause a proper flow of the fluid within the finned tube from theinlet H to the outlet I2, an

inner tube 20 is disposed within the finned tube IS, the tube 20 beingprovided with a pair of oppositely disposed fins or baflles 2|, engagingthe internal surfac of the finned tube lliand thereby dividing'theannular space between the interior of the finned tube l6 and the innertube 20 into two substantially equal arcuate passageways indicated at 22and '23. The inner tube stops short of the end of the'finned tube,leaving a space as at 24, and the ends of both tubes opposite the headerare closed, for example, by plates 25 and 26 welded in position. At theopposite end the tube 20 extends beyond the end of the finned tube l6and into the header, preferably being welded G into place 'within theopening 21 in the boss 28- of the header. The tube 20 and the fins 2|thus function to divide-the chamber l5 in half and to separate the inletand outlet openings. so'that fluid flowing into the exchanger throughthe con-r duit I3 is caused to flow outwardly away from the header.through the passageway 22, then around the end of the tube 20 throughthe space 24, back toward the header through the passageway 23 and outthrough the discharge conduit M. The tube" is employed to reduce thecross-sectional area of the passageways within theflnned tube IS, thetube diameter being selected to pro- "the-desired annular space to givethe proper mass-flow characteristics for the commodities beingcirculated through the exchanger. As will be described below, the tubeis not always necessary or desirable, a flat tongue or baiile beingpreferred for some purposes.

In order to control the flow of the other commodity or fluid passingthrough the heat exchanger, shell tube indicated generally at 29 isprovided. The internal diameter, of the shell tube is preferably justenough largerv than the external diameter of the fins I! to permit thetubes to be assembled-together readily. The assembly thus embodies a.number of parallel, longitudinally extending passageways between theshell tube and the finned tube as shown particularly in -Fig. 2. At theend adjacent the header the shell baifle flns assist in centering thetubes with respect to each other.

The construction of the exchanger is such that the channels between theshell tube and finned tube may be made-accessibl for cleaning either bydisconnecting the two sections of the flnned tube at the flanges 33 and31 and removing the section 35, using the push bolts 40 to break anyadhesion, if necessary, or by disconnecting the header ID from theflange III of the shell tube and pulling out the finned tube from theinside of the shell tube. If the flanges 38 and 31 are disconnected thecleaning operation can be effected without disturbing any one of thefluid connections, and if the exchangers are arranged in a bank'thewhole bank of exchangers will be accessible for cleaning from the endopposite the fluid connections. If the connection is broken, between theheader and the flange 30,

disassembling the exchanger, the shell tube may be made up of twosections 34 and 35 provided with flanges 36 and 31 which may be securedtogether by bolts 38, with a gasket 39 interposed to provide a leakproofjoint. In order to facilitate breaking the connection between thesections, push bolts 40 as shown in Figs. 2 and 5 may be employed. Theend of the section 35 away from the header is closed by any suitableclosure member such as the cap ll welded thereto.

It will 'be noted that the flns l9 terminate adjacent the ends of theinlet and outlet conduits 32 and 33. To insure the proper flow of fluidthrough the passageways formed by the flns between the flnned tube andthe shell tube, the finned tube is provided with a pair of oppositelydisposed baflle fins l2 and 43 shown particularly in Figs. 2 and 4 andwhich extend to the header.

These baflie flns function to divide the annular space between the shelltube and the flnned tube adjacent the inlet conduit and outlet conduits32 and 33 into two zones 44 and 45, respectively. Fluid entering theshell tube through the conduit then it will be necessary to disconnectthe fluid connections to the conduits l3 and I 4 or to the conduits 32and 33, but not to all four of the conduits, and the cleaning operationthen can be carried out from either end of the exchanger.

depending upon which of the conduits are disconnected. Ordinarily if theexchanger is designed for such an installation the shell tube will .bemade in one piece, eliminating the flanges 36 and 31 and the connectionat this point. If the exchanger is designed for the installation firstdescribed above, the flange 21 to which the shell tube is secured may beformed integrally with the header if desired.

To facilitate the handling of the shell tube incident to cleaningoperations, I may provide means for supporting the shell tube inalignment with the finned tube so that 'it' may be moved into and out ofposition with a minimum amount of eflort and without any danger ofdamaging the flns of the flnned tube. For example, section 35 of theshell tube may be provided with U-shaped brackets 53 and SI suitablysecured to the exterior of the tube as by welding, and

to the axis of the flnned tubeand is supported 32 is prevented fromflowing directly around the finned tube to the outlet conduit 33 by thebatfle fins l2 and 43 and is distributed from the chamber 44 into thepassageways formed by the -fln members IS on the lower half of theflnned tube as shown in the drawings. The fluid flows out along thaflnsto the end space 43 and around the flow of the other commodity.

The baflle flns 42 and 43, as well as-the ballle flns 2| on the innertube 23 are preferably formed in such a position that there will beclearance between the flange 31 and the I-beam and that the axes of thefinned 'tube and the shell tube will substantially coincide. By thisarrangement,

withthe flanges of the channels bent as at 41, I

and with the outer edges bent or rolled over as at 43 toprovide aresilient structure. With this construction, the baiile fins can beproportioned to resiliently engage the inner surfaces of the respectivetubes and thus make sealing connections with the tubes adequate toprevent any substantial fshort circuiting" of the fluidsin their flowthrough the exchanger. Further, the

one man can readily disassemble a large heat exchanger, handling a heavyshell tube section that may be several feet long. Supporting tracks ortrolleys are illustrated in the drawings only with respect to this formor my invention. However, it is to be understood that supporting tracksmay be used with the otherforms of my invention, and those skilled inthe art will appreciate that the supports may be modified to suitthe andaccording to the method described and claimed in my copendingapplication Serial No. 388,835, flled April 16, 1941, now Patent2,298,250 issued Oct. 6, 1942, to provide adequate paths for the flow ofheat from the fins to the tube. In Flgs..6 to 8 I have illustratedanother form of heat exchanger made according to my invenfinned tube.

' ployed within the finned tube a tongue such as tion. In this type ofexchanger the header 60 is formed by a plate. having openings BI and 62therein to receive the inlet and outlet conduits 63 and 64,respectively. These conduits are preferably in the form of 90 bends asshown and are provided with suitable means for making fluid connectionssuch as the coupling flanges ila lust'rated. The conduits are preferablywelded into the openings H and .62 and the connection between theconduits and th interior of the finned tube 65 is made by bolting theplate 60 to the flange 66 which is welded onto 'the end of the finnedtube. In this modification instead of employing an inner tube as in theprevious modification, the fluid is caused to flow out to the end of thefinned tube and back again by abaflle or tongue 61 which abuts the plate60 as at 68 and stops short of the closed end 69 of the finned tube,leaving a passageway I around the end of the tongue. Fluid entering theinlet conduit 63 flows out around the end ofthe tongue 61 and backthrough the lower half of the finned tube to the discharge conduit 64.This construction is particularly useful where it is not necessary tohave a high velocity of flow on the inside of the For example, whensteam is emshown in this modification is frequently satisfactory, itbeing unnecessary to employ an inner tube such as shown in the previousmodification.

The heat exchanger shown'in Figs. 6 to 8 is also modified in theconstruction of the shell tube, which is produced from two semi-circularpieces II and 12 having inturned flanges" and .14, the

pieces being. welded together as shown at I and 16. It will be notedthat the inturned flange provides a groove at the juncture of the twopieces, this facilitating arc welding'of the parts. The shell tube issecured to the header assemblyby a flange I1 welded to the end of theshell tube and bolted to the flange 66 which is, as noted above, weldedto-the finned tube and bolted to the header plate 60, suitable gasketsbeing employed where required. Push bolts (not shown) may be employed toassist in breaking these connections if desired. The inlet I8.and theoutlet I9 of the noted, the construction is substantially the same asthat shown and described with reference to Figs. 1 to 5.

In Figs. 9 to 12 a further modificationis illustrated, in which theinlet and outlet connections 1 respect to Figs. 6 to 8 including abailie or tongue I 3 94 which abuts the plate 85 at one end and is fspaced from the closure plate 95 at the other end to provid apassageway. The finned tube is provided with a plurality of fins 96 andoppositely disposed baflle fins 91 and 98, the baflie fins being ofresilient construction similar to fins '42 and 43 and engaging the innersurface of the shell tube 99. p

In order to support the finned tube within the shell tube the finnedtube is provided with a .flange I00 welded thereto near the threaded-endfitting 90. The end of the finned tube is extended through an opening inthe plate IM and the flange is drawn up tightly against the gasket I02,which abuts the plate, by a large nut I03 which is threaded on the endfitting 90'. The shell tube is also supported from the plate IOI, beingprovided with a flange I 04 welded to. the end thereof and bolted to theflange MI.

The shell tube has inletand outlet openings I06 and I0! similar to thosepreviously described but instead of having a welded closure at its end,

shell tube are formed as described above with I respect to the inlet 32and outlet 33.

In this modification the fins 80 on the tube 65 are shown as havingtheir outer edges spaced from the inner surfaces of the shell-tube.-Th1s arrangement is desirable for some services, particularly whereviscous or sticky liquids are circulated through the heat exchangers. Byhaving the fins spaced from the inner surface of the shell tube, thereis less likelihood of the finned tube becoming stuck within the shelltube. To prevent fluid from flowing directly around the finned tube fromthe inlet I8 to the outlet 19, the baffle fins 8| and 82 are employed.These are spring fins of the same general type as described above andengage the inturned flanges I3 and 14 on the interior of the shelltube.' This arrangement provides an adequate seal, and further, thefins-'with their engagement with the flanges I3 and 14 and with theinner surface of necting the connections to the conduits I8 and- 19 andremoving the bolts that connect the.

flange I! to the flange 66. Except for thechanges shell tube.

exchanger can be disassembled for cleaning it is provided with a closureplate I08 which is bolted to the flange I09 welded to the end of theWith this type of construction the either by breaking the connections tothe conduits I06 and I 01 and loosening the bolts securing the flangesIOI and I04 together, which makes it possible to remove the shell tubefrom the finned tube, or the plate 85 may be disconnected from the endfitting 90, the nut I03 unscrewed from the end fitting and the end plateI08 removed, thus permitting the finned tube to be removed from theexchanger from theend opposite the fluid connections.

From the foregoing description of preferred forms of my invention itwill be seen that I have provided compact heat exchangers which can beeconomically manufactured. By reason of the counter-flow principlepreferably embodied in my exchangers and the arrangement of the tubesand battles, very eflicient heat exchange characteristics are obtained,thus providing exchang-. ers which can take advantage of the high heatas in such instances it is very difficult to make leak-tight connectionsand it is desirable to maintain' the connections without disturbingthem,

The interior arrangement of even though the exchangers should requirecleanmg.

The heat exchangers disclosed herein prefer ably embody finned tubingmade according to my application aforesaid; however, it is to beunderstood that different types of heat exchanger conductors can beemployed if desired. Also, features described with respect to any oneform 'of 'the interior of the inner of said tubes, an inlet conduit andan outlet conduit connected to the annular space between said tubes, allof said conduits being disposed adjacent one end of the heat exchanger,means closing the end of said annular space adjacent said end of theheat exchanger and both of said tubes being closed at the opposite endof said heat exchanger, baflle means within the inner of said tubesdividing it into two longitudinally extending passageways communicatingwith each other only adjacent the closed end thereof, the inlet conduitfor the interior of said inner tube being connected to one of saidpassageways and the outlet conduit therefor being connected to theother, and bailie means within said annular space dividing said spaceinto two longitudinally extending passageways.com- ,municating with eachother only adjacent the closed ends of said tubes, the inlet conduit forsaid annular space being connected to one of said passageways thereinand the outlet conduit for said annular space being connected tothe.othersaid passageways therein, both said baflle means lying in thesame general longitudinal plane of the heat exchanger.

2. A heat exchange comprising two concentric -tubes with an annularspace therebetween; an

inlet conduit and an outlet conduit connected to the interior of theinner of said tubes, an inlet conduit and an outlet conduit connected tothe annular space between said tubes, all of said conduits beingdisposed adjacent one end of the heat outlet conduit therefor beingconnected to the other, said inner tube being provided with a pluralityof longitudinally extending external fins, andbaflle means within saidannular space dividing said space into two longitudinally extendingpassageways communicating with each other eral longitudinal plane of theheat exchanger.

3. A heat exchanger comprising two concentric tubes with an annularspace therebetween, an inlet conduit and an outlet conduit connected tothe interior of the inner of said tubes, an inlet conduit and an outletconduit connected to the annular space between said tubes, all of saidconduits being disposed adjacent one end of the heat exchanger, saidtubes being detachably secured together adjacent said conduits and bothof said tubes being closed at the opposite end of said heat exchanger,bafile means within the inner of said tubes dividing it into twolongitudinally extending passageways communicating with each other onlyadjacent the closed end thereof, the inlet conduit for the interior ofsaid inner tube being connected to one of said passageways and theoutlet conduit thereforjbeing connected to the other, and bafliemeanscomprising two oppositely disposed longitudinally; extending flnmemberssecured to said inner tube and engaging said outer tube dividingsaid annular space into two longitudinally extending passagewayscommunicating with each other only adjacent the closed ends of saidtubes, the inlet conduit for said annular space being connected to oneof said passageways therein and the outlet conduit for said annularspace being connected to the other of said passageways therein, bothsaid baflie means lying in the same general longitudinal plane of theheat K exchanger.

JOHN w. BROWN, JR;

